A downhole plug is designed to provide zonal isolation in a wellbore (i.e., to isolate a portion of the wellbore above the plug from a portion of the wellbore below the plug). One type of plug includes a mandrel having a bore formed therethrough, which may be plugged by an obstruction such as a ball, or may have a permanent obstruction or “bridge” therein.
The plug is typically secured in place (or “set”) in the wellbore by actuating a setting assembly. For example, a slip, a cone, and a sealing element are positioned around the mandrel. When the plug is in the desired position in the wellbore, a setting tool may apply opposing axial forces on the plug that cause the slip to slide along an inclined outer surface of the cone, which pushes the slip radially-outward. As the slip moves radially-outward, teeth on the outer surface of the slip may engage a surrounding tubular (e.g., a liner, a casing, a wall of the wellbore, etc.) to secure the plug in place in the wellbore. The opposing axial forces generated by the setting tool may also cause the sealing element to expand radially-outward to contact the surrounding tubular. When in contact with the surrounding tubular, the sealing element may prevent fluid from flowing axially through an annulus formed between the mandrel and the surrounding tubular.